Today is designated as the official day as the first three digits of pi are 3.14 which, in the American calendar, equates to March 14.

To celebrate Pi Day Cymru, pupils from Llanfechell Primary School took part in a renaming ceremony at “Llanfair πG” station - ordinarily called Llanfairpwll - before using Pi to measure circular objects at the station.

The idea for Pi Day Cymru came from retired professor Gareth Ffowc Roberts, who has received the official backing of the Welsh Government for the celebration.

Mathematician William Jones was the first person to use the Greek letter π (pi) (Image: National Portrait Gallery)

Meinir Roberts, headteacher at Ysgol Llanfechell, said: “We always celebrate our local connections to Pi during maths lessons and are delighted to be involved in the first official Pi Day Cymru.

“I hope that by making this an annual celebration it will give teachers an added reason to focus on Pi during lessons on this day each year, as well as providing an opportunity to have some fun with the use of Pi.”

Llanfairpwll, also referred to by some as Llanfair PG, is short for Llanfair­pwllgwyngyll­gogery­chwyrn­drobwll­llan­tysilio­gogo­goch which is thought to be the longest place name in Europe.